As said beautifully in this breaking muscle article:
“the overhead squat is a punk.” It gives even the most enthusiastic Crossfitters the blues. But what can be done, aside from relentless drills and practice, to remedy this all too familiar frustration? MOBILITY. As referenced in the article and documented thoroughly, lack of mobility is partly to blame for your overhead squat blues. This is specifically true of your ankles, and your upper body including your mid back (or thoracic spine ), and the pectorals, lats and triceps. Good news? This is fixable. You don’t have to struggle with the overhead squat, and by proxy your snatches, forever. Bad news: it’s a long road that takes diligence. Gone are the days when you thought you could bench a ton and not stretch out afterward. Spend some extra time stretching out those amped up muscles with a band, foam roller or a lacrosse ball. Always take a moment after a tough lifting day and give your upper body and ankles some extra mobility TLC. The next time you do Isabel or Nancy, you’ll be thanking yourself for your efforts.